Tag: particle physics

Four years ago, artist Kate Findlay was reading an article about the Large Hadron Collider. When she saw photographs of the collider’s experiments, she, like many others since the project began, was struck by their beauty. But unlike most particle physics spectators, she set out to make art from them—using cloth. “The LHC is a remarkably beautiful machine. Its symmetry, the repeating motifs, [and] the colors were all things that I was drawn to–for any textile artist, pattern and color are top of the list and the LHC has all these!” she told PopSci in an interview last week.

What’s the News: An international team of researchers has completed the most precise measurement of the Earth’s radioactivity to date. By analyzing subatomic particles streaming out of the interior of the planet, the geologists and physicists discovered that the radioactive decay of several elements generates roughly half of the Earth’s total heat output. Their results were published recently in the journal Nature Geoscience.

Researchers report this week in Nature that they’ve managed to corral atoms of antimatter in the lab and keep them around for about one-sixth of one second—an eternity in particle physics. The ability to trap these atoms means scientists could soon have the ability to study them directly, and perhaps answer one of the fundamental questions of the universe: Why the matter and antimatter present after the Big Bang didn’t annihilate each other completely and leave a matter-less universe behind.

It’s not easy, because of that mutual-annihilation issue. Hangst said the first trick was to combine the particles in a super-cold vacuum setting — less than 0.5 Kelvin, or -458.8 degrees Fahrenheit. That way, the particles don’t instantly jump away and fizzle out. The second trick is to build a magnetic trap to help contain the particles so that they don’t instantly decay. And there’s a third trick: designing a system capable of verifying that the atoms actually exist. “You must have a trap, and you must be cold, and you must be able to detect that you’ve done this,” Hangst said. [MSNBC]

Detectors buried thousands of feet under the Antarctic ice recently confirmed a mysterious cosmic lopsidedness. Though it might seem reasonable for our planet to receive energetic particles, called cosmic rays, on average from all directions equally, more cosmic rays’ seem to approach Earth from certain preferred directions.

The IceCube Neutrino Observatory, which is still under construction, confirmed these odd cosmic ray preferences, previously detected in the northern hemisphere.

Cosmic rays–energetic particles flung from as nearby as the sun and light years away–are the extra “noise” in the observatory’s experiments; to filter out this noise, researchers needed to map where the cosmic rays are coming from. In a paper published earlier this month in The Astrophysical Journal they confirmed that more cosmic rays seem to come from certain directions–an observation known as anisotropy–in the Earth’s southern hemisphere too.

[T]hey used IceCube to study a longstanding puzzle: whether the distribution of cosmic ray arrivals is uneven across the southern sky, as scientists have previously observed in the northern hemisphere. Indeed, the team found, IceCube detected a disproportionate number of cosmic rays arriving from some parts of the sky. But the reason for this uneven distribution remains unclear. [ScienceNOW]

It wasn’t supposed to be like this. The Higgs boson, dark matter, neutrinos—weird or poorly understood phenomena like these seemed the likely candidates to provide a surprise that changes particle physics. Not an old standby like the proton.

But the big story this week in Nature is that we might have been wrong all along in estimating something very basic about the humble proton: its size. A team from the Paul-Scherrer Institute in Switzerland that’s been tackling this for a decade says its arduous measurements of the proton show it is 4 percent smaller than the previous best estimate. For something as simple as the size of a proton, one of the basic measurements upon with the standard model of particle physics is built, 4 percent is a vast expanse that could shake up quantum electrodynamics if it’s true.

If the [standard model] turns out to be wrong, “it would be quite revolutionary. It would mean that we know a lot less than we thought we knew,” said physicist Peter J. Mohr of the National Institute of Standards and Technology in Gaithersburg, Md., who was not involved in the research. “If it is a fundamental problem, we don’t know what the consequences are yet” [Los Angeles Times].

As a younger stronger particle smasher, the Large Hadron Collider can turn even baby steps into new records. Over this past weekend, the LHC beat another personal best–colliding its most protons yet at 10,000 particle collisions per second (about double its earlier rate). Physicists believe this is a crucial step on the collider’s hunt for new physics.

In November of 2009, the LHC collided its first protons as it started its quest to find the suspected mass-giving particle known as the Higgs Boson. The collider is still running at half of its designed maximum energy, but after this weekend, the number of particles per bunch traveling in the ring is just what physicists had planned. This is essential, says CERN physicist John Ellis:

“Protons are complicated particles, they’ve got quarks, [and other small particles], and colliding them is like colliding two garbage cans and watching carrots come out…. The more collisions we get, the closer we get to supersymmetry, dark matter, the Higgs boson and other types of new physics.” [BBC]

If the Higgs boson is the “God Particle,” then some particle physicists just turned polytheistic. To explain a recent experiment, they wonder if five Higgs bosons give our universe mass instead of one.

Last month, we discussed a curious experiment at the Tevatron particle accelerator at Fermilab near Chicago. Colliding protons and antiprotons, the Tevratron’s DZero group found more matter than antimatter.

This agrees well with common sense–if the Big Bang had really churned out equal amounts of matter and antimatter, the particles would have annihilated each other, and we wouldn’t be here. Unfortunately, the physics for this matter favoritism doesn’t make sense.

For one, it requires some fudging to fit the Standard Model, the organizing theory for particle physics. This might seem sad since we were so close to finishing the Standard Model up, with the Higgs filling the last cage in physicists’ particle zoo:

For those who believe the Standard Model is nearly complete, the discovery of the Higgs boson–a theoretical particle that imparts mass to all the other particles–would close out the final chapter. But for others who think that undiscovered physics properties exist–so-called new physics–a sequel to the Standard Model is needed. [Symmetry]